I just installed a 2.5" turbo back exhauston my s4 the only other mods are a cone intake and apexi BOV. Im boosting 10-12 PSI, in 1st and 2nd gear boosts to 12 then drops in high RPM boost creep I assume havnt ported the waste gate. I was wondering whats a safe boost level and what else I should do so I dont blow my engine up????

Thanks